Department of Radiology, Otaru General Hospital.
Department of Neurosurgery, Otaru General Hospital.
Magn Reson Med Sci. 2019 Jan 10;18(1):36-43. doi: 10.2463/mrms.mp.2017-0078. Epub 2018 Mar 23.
To compare the accuracy of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values between reduced FOV or so-called zonally oblique multislice (ZOOM) and conventional diffusion tensor imaging (DTI) in the cervical spinal cord.
Both ZOOM and conventional DTI were performed on 10 healthy volunteers. Intraclass correlation coefficient (ICC) was used to evaluate the reliability of the measurements obtained. Four radiologists evaluated the FA and ADC values at each cervical cord level and classified the visibility by 4 ranks. The geometric distortion ratios of the long axis and short axis were compared between ZOOM and conventional DTI. The imaging parameters were as follows: b-value = 600 s/mm; TR = 4500 ms; TE = 81 ms; FOV = 70 × 47 mm / 200 × 200 mm; matrix = 80 × 51 / 128 × 126 (ZOOM and conventional DTI, respectively). The region of interest was carefully drawn inside the spinal cord margin to exclude the spinal cord component, without excluding the white matter fiber tracts.
The average FA value decreased in both ZOOM and conventional DTI in lower spinal cord levels; in contrast, the ADC value increased in lower spinal cord levels. Zonally oblique multislice DTI was superior to conventional DTI with regard to inter-rater and intra-rater reliability; further, visibility was better and the standard deviation was smaller in ZOOM DTI. On both the long and short axis, the geometric distortion ratio was lower in ZOOM DTI at all cervical spinal cord levels compared with the conventional DTI. There was a significant difference in the distortion ratios of the long and short axis between ZOOM and conventional DTI.
Conventional DTI is unreliable owing to its susceptibility to the surrounding magnetic field. ZOOM DTI is reliable for performing highly accurate evaluations.
比较减少视野（FOV）或所谓的带状斜多切片（ZOOM）与常规弥散张量成像（DTI）在颈脊髓内的分数各向异性（FA）和表观扩散系数（ADC）值的准确性。
对 10 名健康志愿者进行 ZOOM 和常规 DTI 检查。采用组内相关系数（ICC）评估测量值的可靠性。4 名放射科医生在每个颈髓水平评估 FA 和 ADC 值，并进行 4 级分类。比较 ZOOM 和常规 DTI 的长轴和短轴的几何变形比。成像参数如下：b 值=600 s/mm；TR=4500 ms；TE=81 ms；FOV=70×47 mm/200×200 mm；矩阵=80×51/128×126（ZOOM 和常规 DTI，分别）。感兴趣区域仔细绘制在脊髓边缘内，以排除脊髓成分，而不排除白质纤维束。
在较低的脊髓水平，ZOOM 和常规 DTI 的平均 FA 值均降低；相反，ADC 值在较低的脊髓水平增加。在观察者间和观察者内可靠性方面，带状斜多切片 DTI 优于常规 DTI；此外，在 ZOOM DTI 中，可观察性更好，标准差更小。在所有颈脊髓水平，与常规 DTI 相比，ZOOM DTI 的长轴和短轴的几何变形比均较低。ZOOM 和常规 DTI 之间的长轴和短轴变形比存在显著差异。
由于周围磁场的影响，常规 DTI 不可靠。ZOOM DTI 可靠，可进行高度准确的评估。
